1. The Field of the Invention
The embodiments disclosed herein relate to electromagnetic imaging of geological formation. In general, the embodiments disclosed herein relate to formation evaluation, imaging-while-drilling and look-ahead imaging using borehole devices measuring multi-component vector and/or tensor electromagnetic logging data.
2. The Relevant Technology
A multi-component induction logging tool was originally introduced for resolving anisotropic geological formations (e.g. as described by Fanini, et al. in U.S. Pat. No. 6,677,756 and U.S. Pat. No. 6,900,640; and by Kriegshauser et al. (Improved shale sand interpretation in highly deviated and horizontal wells using multi-component induction log data: 42st Annual Logging Symposium, SPWLA, Transactions, paper S and An efficient and accurate pseudo 2-D inversion scheme for multi component induction log data: 71st Annual International Meeting, SEG, Expanded Abstracts, 376380). This instrument has three mutually perpendicular magnetic induction receiver coils and three magnetic induction transmitter coils.
The foundations of tensor induction well logging (TIWL) in anisotropic geological formations were outlined in papers by Zhdanov et al. (Foundations of tensor induction well-logging: Petrophysics, 42, 588-610 and Principles of tensor induction well logging in a deviated well in an anisotropic medium: Transactions, 42-nd SPWLA Annual Logging Symposium, Houston, paper R).
It was demonstrated by Zhdanov in U.S. Pat. No. 6,253,100 that the methods of optical and radio holography can be extended to a broad band electromagnetic (EM) field for imaging objects in nontransparent media by a system of electric and/or magnetic transmitters and receivers placed at different positions around the object.